Being fat and being healthy are not mutually exclusive events. Your eating and physical activity habits are (far) more important predictors of your health than a number on the scales.

Since we live in a time that says our body is an important part of who we are, believing or promoting this idea that fatness is bad is a recipe for body shame and emotional stress – two potent risk factors for overeating, fad dieting, mental illness, suicide and chronic disease.

Helping fat people to practice body and self-acceptance has been proven to enhance physical and mental health more so than dieting does. And no, self-acceptance does not make people eat ‘worse’ – research demonstrates the very opposite is actually true.

The idea that who we are is equal and enough may just be the most powerful tool we have invented to improve the health and wellbeing of our society as a whole.

And this time, the wellbeing of future generations falls on us.

[Note: This post originally claimed, “There is zero scientific evidence that diet and exercise results in significant weight loss in the long-term.” This was an exaggeration of the evidence and thus has been edited accordingly.]

I was cleaning out my study the other day when I came across a dated nutrition book. Flicking through the pages, its central theme was one you have surely heard of: eating less fat will help you to lose weight and find better health.

It may vary between fat, sugar, carbohydrate or fructose, but my experience is that most popular nutrition books are based on this idea.

Important to understand, then, that nutrition is never actually linear, and always far more complex. For example, our current understanding of the relationship between fat, weight gain and health changes according to numerous variables. Here are just a few:

There are many different types of fatty acids, some which have vastly different health effects from others.

The quantity of fat that is consumed changes the health effect; consuming some fat is healthier than avoiding it entirely or consuming it in excess.

Foods contain much more than just fat, and some high-fat foods can be rich (or poor) sources of health-promoting nutrients like dietary fibre and antioxidants.

Eating less fat typically means that we will eat more of something else, and the health consequences of eating less fat are very dependant on what that something else is.

Fat consumption can improve the absorption of other essential nutrients, and the health consequence of this depends on your current intake of these nutrients.

Believing a low-fat diet is ‘good’ can actually increase our consumption of low-fat cookies and other low-fat discretionary foods.

How fat is cooked can change its chemical nature and subsequent health effect.

There is a wide variation in the metabolic response between individuals, even after digestion of the very same food. What works for one individual may not work for another.

Telling people to avoid the foods they enjoy can make them crave and overeat them even more.

Our beliefs about the health effects of what we eat likely affect their actual health outcome.

We live in a complex world, and it’s human nature to try and simplify it. To remove the many moving variables at play so that it fits into our current level of understanding. I think that’s why we mostly look at nutrition through a linear lens, arguing that the solution lies in avoiding fat, sugar, starch, salt, grains, dairy, soft drink or bread.

In reality, though, the better solution exists at the higher levels of thinking.

Thinking that considers the wider variables, understands their interconnectedness, recognises the ambiguity and appreciates the complex.

How does this simple exercise work? Consider the following (and quite remarkable) scientific research:

Kindness increases happiness. Just thinkingaboutsendingkindness to othersrewires the brain in a positive way, and doing the exercise I described here boosts happiness levels, on average, by more than 10%.

Happiness, in turn, further increases kindness. For example, in controlled research it has been shown that you are 4 times more likely to help another after you have been made to feel good.

Happiness is highly contagious. If you become happy, you increase the probability that your next-door neighbour is happy by some 34%. Furthermore, becoming a new happy friend to someone can boost not only their long-term happiness by more than 4 times what them winning $15 000* would, it can even significantly boost the happiness of a friend, of a friend, of your friend!

Your emotions and behaviours are highly contagious. And because we live in extraordinarily complex social systems, they will spread far beyond what you can see, and have an impact on people who you will never meet.

How you live your life, matters.

More so than you can ever know.

[*estimated value after converting to $AU and accounting for inflation.]

There is little evidence that high-fat dairy foods are unhealthy. Indeed, research finds cheese (the dairy food with the highest density of fat) may actually promote heart health more so than other dairy foods.

I’ve heard advice not to eat full cream dairy (it’s high in fat!), not to eat low-fat dairy (it’s high in sugar!), not to eat cheese (it’s high in calories!), not to have cow’s milk (it’s not fermented!), and not to eat any dairy at all (it’s not natural!).

Yet my interpretation of the nutrition research is that all can be compatible with good health; yet none are essential for it.

An important nutrition principle is the one of replacement: for every food (or nutrient) you remove from the diet, another usually takes its place.

One common limitation I see with many popular diets is that they fail to appropriately advise on replacement. Low sugar, low fat and low carb can each be effective for better health and body weight. But they can each be pointless exercises, too.

Perceiving your daily activities as exercise can result in significant drops in weight, waist circumference and blood pressure, without any actual changes to your reported eating or exercise.

Having a make-over decreases your blood pressure, but only if you perceive that it makes you look younger.

Pretending to be a pilot improves your vision by around 40%.

Your blood sugar level (if you are diabetic) will rise and fall based more on your perception of time, than the actual time.

Imagining yourself getting the cold makes you 4 times more likely to actually get it.

Viewing your cancer (if you are a cancer survivor) as ‘cured’, as opposed to ‘in remission’, correlates to you being physically healthier, more energetic and less depressed.

You have about a 1 in 3 chance of healing yourself from virtually any disorder if you are given a placebo (an effect that remains even if you know it is a placebo).

Pretending you have travelled back in time (if you are elderly) significantly improves your strength, flexibility, posture, height, weight, hearing, vision, arthritis, and makes you look physically younger (!!) when judged by people blinded to the study.

Each of these scientific findings makes good sense when we see our mind and body as deeply connected, and understand that our beliefs are far more important than we give them credit for.

If you have a health problem that you can’t overcome, I think it is at least worth asking: is it because I actually can’t, or because I have been living in a society that has made me think that I actually can’t?